Abstract

The headache histories obtained from clinical interviews of 600 patients were analysed by computer to see whether patients could be separated systematically into clinical categories and to see whether sets of symptoms commonly reported together differed in distribution among the categories. The computer classification procedure assigned 537 patients to the same category as their clinical diagnosis, the majority of discrepancies between clinical and computer classifications involving common migraine, tension-vascular and tension headache. Cluster headache emerged as a clearly-definable syndrome, and neurological symptoms during headache were most prevalent in the classical migraine group. However, the classical migraine, common migraine, tension-vascular and tension headache categories differed in terms of the number, rather than the nature, of common migraine features. Whether the two extremes of this migraine-tension headache spectrum are different disorders can be determined only by studies of their pathophysiology.